Power generation continues to be an important application of rotating electrical machines. Wind energy is one of the fastest growing sources of electricity around the world, and wind turbines employing rotating electrical machines are used to convert wind energy to usable power. Some conventional wind turbines include a turbine rotor having turbine blades and an output shaft which drive an electrical machine that can supply 3-5 Megawatts of power to the utility power network. However, increased power demand is leading to increased power requirements for each wind turbine. To obtain a wind turbine that can deliver 10 Megawatts or more, a mere scaling up of the size of the conventional geared power train becomes impractical, due at least in part to the size, weight, cost and potential unreliability of a gearbox which can accommodate these requirements.
High temperature superconducting (HTS) coil windings are proposed for use in ultra low speed, direct drive generators for wind turbines that can produce power at levels of 10 megawatts (MW) or more. In order to achieve power production at this rate, improved HTS electrical conductors used to form the coil winding may be required.
Design and fabrication of HTS electrical conductors for use in power transmission cable applications has been focused on providing a cable having low loss, high current transmission over great distances, as well as providing a cable having some flexibility. The design and fabrication techniques for forming HTS electrical conductors are also used to form electrical conductors used in coil windings of generators used in power generation applications. However, since the arrangement and loading conditions of an electrical conductor in use within a power transmission cable is quite different than that of a conductor within a generator coil winding, HTS electrical conductors adapted for use in coil windings are required.